Uncle’s teapot clearly is Yixing pottery also know as “Purple Sand Ware”.
Yixing teawares are prized because their unglazed surfaces absorb traces of the beverage, creating a more complex flavour. For these reasons, yixing teawares should never be washed using detergents, but rather with water only, and connoisseurs recommend using each tea vessel for one kind of tea (white, green, oolong, or black) or sometimes even one variety of tea only.
Sure sounds like Uncle to me, doesn’t it…
Take a closer look at the design, while Yixing pots are usually unglazed and a beautiful shade of brown, they do come in glazed varieties. Especially note the spout and the handle. Uncle uses a variation on the ‘Dragon, Phoenix and Petal design.